hi! from a newbie in canada. rb25det neo, in 240sx

[polemite]

hi everyone! i'm just getting started with nistune in my neo powered s13.5, 240sx.
i'm currently reading up on nistune documentation, and scanning these forums, but i have some questions, so i'd really appreciate some simple answers or reference data to check out.


the engine is originally out of a manual trans GT-T
the ecu is a manual trans GT-T aa502
but...
the nistune board is 0v81f , which is apparently an awd auto stagea.

matt was kind enough to advise me that this combination should work just fine, with the exception of having to disable the trouble code for the auto trans coms. i've accomplished this so far, thank you matt!

my current project, is getting the boost sensor operational.
i am using a plug n play wiring conversion harness from wiring specialties. but back in 2015 when i bought it, they didn't include the boost sensor wiring with the harness. they were kind enough to send out a plug with a pigtail that reaches back to the ecu. i now have it installed, but i'm getting some strange warning messages about it.

caution: boost pressure dtc disabled- fix or scale tp load to max 132

i checked, and the dtc flag for the boost sensor is still ticked.
i set max sensor voltage to 5100mv, min to 60mv.

this got me to where i can idle without any faults, after clearing. but if i blip the throttle, it comes back.
nistune recommended that i check the voltages at the sensor.
i do measure 5v at the plug, so i know that both the sensor power and ground wires are intact and working.
back on the consult screen i have a reading of 2.60 for the boost sensor at idle, and i can get it to move up to about 2.70 when i blip the throttle.
i tried moving my vac line source from before the throttle body, to an unused line off the manifold, and the reading dropped to ~1.7

so i have to assume that the sensor signal is getting back to the ecu, right? what gives?
does the sensor also use a chassis ground reference? i wouldn't think so, but currently i do not have the sensor mounting bracket bolted to the chassis.
i've been back and forth through the program features, and i can't find any other place where the boost sensor may be disabled. am i missing something? another setting of some sort?

[polemite]

other questions:

1.
looking at the rev limiter settings, this is what i found:
soft limit- 12,xxx
hard limit- 6600
limit recover(?)- 6400

-what is the soft limit?
-6600 seems kinda low, doesn't it?
-where do you normally set these?

2.
there are a ton of features related to purge control.
-am i right to assume that this is referring to the fuel vapor canister/recirc system?
-if so, why are there so many features for it?
*i did not install any of these parts in my car when i did my swap.

3.
i did not install the oem boost solenoid when i did the swap. instead, i just added a manual turbosmart boost tee. currently set to stop at 9psi.
-is there any reason why i'd want that solenoid in there?
*future plans are to go to a top mount manifold and external wastegate. feeding the engine non ethanol, 94 octane pump gas. not planning on ever going beyond 400hp.

[Matt]

There is more than one boost pressure (maybe MAP unticked?) DTC tickbox. Compare your tune against factory to see which DTCs were altered. Why you are still getting the error

Soft limit will temporarily cut injection, and hard limit will cut injection until down around 2000rpm

Get rid of stock solenoid, don't need it. Purge is for EGR feedback. Don't need to change anything there

[polemite]

oh good, sounds like a simple fix. i'll check it out tomorrow.

thanks for the info on the other stuff. glad i can ignore most of it.

hard limit takes it all the way back down to 2000rpm eh? wow.
so just off the top of my head, i'm thinking
soft limit 7200
recover 7000
hard limit 8000

seem reasonable?

[Matt]

Normally hard takes it down to hard RPM recover. Not sure if that is 7000 at the moment on yours

[polemite]

yup, the map dtc tickbox wasn't checked. fixed that.

also moved the rev limits.

but oddly, i was getting some strange codes for a bit.
ecu boost limiter reached. increase limit counter
ecu speed limiter reached.
ecu load (tp) limiter reached.

i was getting all these just from throttle blips in the shop.
i cleared the codes, increased the boost limit counter to 255, from 10
speed limit was already at max
load limit was at 10. didn't touch it.

blipped again and got the codes again. cleared codes, burnt changes, stopped and restarted. no codes. drove to the gas station and monitored consult the whole way. no new codes.
so i guess that's what it needed, but now i'm wondering if i should have changed that boost limit counter?

[Matt]

They are not codes, but warnings if load amounts from ECU go over what is in the logs then I raise it as a potential issue. People kept asking me why they were getting cuts etc, so I try and detect what might be the issue and put it as a status message. Only the DTC window has ECU 'faults'

[polemite]

ahh! thanks for the clarification.

haven't been driving too much, but the car is feeling excellent so far. could be the cool air we're getting in the mornings, but the response feels pretty damn crisp!

can't wait to get the wideband working with this. but i'm gonna wait till i can get the turbo rebuilt and hiflowed.

[polemite]

super frustrating- i just tried to make a big post, and got logged out in the mean time. lost the entire thing.
round 2.

i'm looking ahead to my winter projects, and kicking around some thoughts. figured i'd check in here to make sure i'm on the right track.

goal is to be a 350-400whp street car, running on 94 octane, that has an epic exhaust note.

current wishlist is:
plazmaman top half plenum (r33 throttle body)
sinco turbo manifold (best sound i've heard so far)
gtx30 based hiflow turbo
audi r8 coil conversion

current parts bin contains:
gfb tms resons bov
tial 38mm ewg
deatschwerks drop in 440cc injectors
r35 maf and 3.5" pipes to fab an inlet with
aem uego wideband
catch can
fresh 255lph fuel pump(don't know the history on the current one)

currently installed supporting parts:
clutch/flywheel setup
fmic
nismo adjustable fuel pressure reg (hoping to keep the oem fuel rail)
turbosmart boost tee

also have an ac/dc tig welder to fab with. (inlet pipe/ic pipes/recirc line/downpipe/new exhaust)

questions are:
1. do i have all the right ingredients? am i forgetting anything?
2. from a nistune perspective, should i follow a certain order for installing this stuff, or do it all at once, and resize/tune all at once?

[Matt]

Read our tuning guides, you will see we recommend to do one thing at a time... that way if something goes wrong you know what it is

You can do injectors firstly for example and then dial those in and make sure it working before doing the MAF

[polemite]

right on. i just seemed to remember reading something that said you should do things together, in order to keep the scales relative to each other? i guess i understood that wrong.


but the intake plenum, throttle body, and bov will have to go together. i'm thinking that can be step 1.

step 2 can be the turbo, manifold, ewg, downpipe, and wideband

step 3 coil pack upgrade

step 4 fuel pump

step 5 injectors

step 6 maf/intake

[Matt]

Yes that sounds good. Maybe do coils at the end. At least Step 1/Step 2 you will know if any airleaks etc before moving onto injectors / MAF later on

Yes sometimes we do injector/MAF change together but you can do injectors firstly in most cases and check those before MAF and then tune it properly afterwards

[PL]

Just reading this now....

Sounds like a great project. I've done quite a few NEO engines and I like them a lot.

Some points that might help:

- Make sure your VCT is working. It makes a big difference.
- Don't get greedy on turbo size. GTX3071 is a nice size and will give around 500hp. I did one with a 2871 (56t) re-core on stock housings recently and it was very good too - ran out of injector at around 400hp but looked like making about 430hp once we get bigger injectors. Also did one with GTX2863R - small turbo so great response - 410hp. 3076 is too big IMHO - lots of power but very laggy.
- They do respond well to Poncams.
- Your 440cc injectors are probably going to be too small. I've had excellent results with R35 GTR injectors. 570cc. Can be had cheap. Multi-hole (12 from memory) tip so good atomisation/pattern.

PL

[polemite]

thanks for the info pl!

the main turbo guy up here said that he can built 2 turbo options-
gtx28 based- which he says spools as good or slightly better than stock, but tops out between 375-400hp
or gtx30 based- which spools up marginally slower than stock but has more up top (can't remember the specific number)

i figured i'd go with the bigger one, so i'm not maxing it out, but in reality i wouldn't be asking for all 400hp very often... what you're saying about the gtx28's has me rethinking it.

i bought the deatsch 440's based on the calculator on their website. you really think that's going to be too small?
i'll certainly defer to real world experience, if that's the case. but another limiting factor is my clutch. off the top of my head i think it's rated to hold 415ft/lbs.


only 2 more weeks of insurance, before it gets put to bed for the winter. getting cold up here, so i don't even know if i'll drive it that long.

plazmaman plenum is ordered! looking forward to getting started on that.

[polemite]

oh yeah- how do you normally like to verify the vct? just watch through nistune? i seem to remember that being in there. i never really thought about checking it, till you mentioned it. is that something that often fails?

if so, it makes me wonder about a cut that i get on hard acceleration, at about 6200rpm. however- i can't even confidently say that my tach is right. it's still the 4cyl tach, but adjusted via the pot on the back. dialed it in at idle, and it seemed good revving to 2k sitting in the shop. but i never verified that on a real pull. i could very well be hitting the rev limit... or the limits of the unknown fuel pump that came with the car, or who knows what else. i don't mess with it much when i'm daily driving.